Casting machine



Nov. 25, 1930.

C. E. HUNTER ET AL CASTING MACHINE Filed April 30, 1930 2 Sheets-Sheet l 38 Z5 1 3Q 27 f i I A 6 /23 Z5 2 2y 3/ 4 a l R \I l/ v za A [5&2 l2 E 5 '7 fM zfia a 62/2 flay/Zr- Ja {0/ 1930- c. E/HUNTER ET AL 1,782,898

CASTING MACHINE Filed April 30. 1950 2 Sheets-Sheet 2 IA III/ll Patented Nov. 25, 1930 PATENT OFFICE CARL E. HUNTER AND DE L. LU'IZ, OF MEIVIIHIS, TENNESSEE mm MACHINE Application filed April 30,

This invention relates to improvements in machines for making castings by centrifugal molding, that is, improvements in machines which throw the molten metal by centrifugal force, into a mold and by the same force hold the metal in place in the mold until it has. cooled. Primarily the invention relates to machines for making small metal castings, such for instance as the gold castings used in dental work.

The objects of this invention are:

(a) To provide .means whereby molten metal will be thrown outward into a mold by centrifugal force;

(b) To provide means for initially positioning the parts of the machine to facilitate placing the molten metal at the entrance to the mold; Y

(c) To provide means whereby the throwing arm will be initially actuated by the same amount of force in each use of the machine;

(d) To provide means for entirely releasing the throwing arm from the actuating means at a'predetermined time; and

(e) To generally improve the design and construction of such a machine.

The means by which the foregoing and other objects are accomplished and the manner of their accomplishment will readily be understood from the following specification on reference to the accompanying drawings,

in which: a

Fig. 1, is a side elevation of the machine mounted on .a base, and with the throwing arm positioned in the normal initial horizontal position.

Fig. 2, is a plan with the throwing arm horizontal, as shown in Fig. 1. f

Fig. 3, is a view of the same side of the machine as that shown inFig. 1, with the front part of cover plate removed.

' Fig. 4., is a sectional elevation taken on the line IV-IV of Fig. 3.

5, is an enlarged section tal en on the line %-V of Fig. 3.

' Fig. is a similarly enlarged end view of the mold.

Fig. 7, a fragmentary sectional elevation on the line VII-VII of Fig. 6; and

1989;? Serial Nb. 448,693.

8, an enlarged fragmentary sectional elevation on the line VIII of Fig. 3. I

Referring now to the drawings in which the various parts are indicated by numerals, 10 is a base which may have a drawer 11 I therein. 12 is a melting furnace.

Mounted on the base 10 is a hollow stand 13, in which is disposed the actuating and driving mechanism. Preferably this stand is rectangular in cross section and comprises a front part 14, and rear part 15, which are secured together as by screws 16. Each of the parts has a horizontally extending flange 17, 18 respectively, which flanges support the stand on the base 10 and which maybe secured thereto in any desired manner.

19 is' a horizontal shaft mounted in a bearing 20 carried by the rear part 15, one end of the shaft projecting within the stand and the other outside thereof. 21- is a pinion secured on the shaft, withinthe stand, and 22 is a hub secured on the shaft outside the stand.

23 is a, throwing arm, secured to the hub 22 and extending outward in opposite directions therefrom, and at right angles to the shaft 19.

24 is a balance weight which 'is slidably mounted on the arm 23 and is provided with a set screw 25 by which it may be clamped to the arm in any desired position.

Disposed and secured on the opposite end of the arm is a mold holder 26, w ich carries a crucible 27 ofrefractory material in which the metal to be cast may be melted or into which such melted metal may be poured.

This crucible is held in place by a cli 28 preferably engage grooves in the sides of the crucible.

Integral with and extending fromthe 'holder 26 is an annular boss 30 exteriorly having inwardly turned flanges 29 w ich leads from the slot 35 partially around the ring and permits rotative movement of the ring relative to the pin 33. When so rotated the shoulder 37 of this groove engages the outer side of the pin and clamps the mold shell solidly in place. A m'old 38 is formed in usual manner in the shell 31.

39 is a vertically disposed slide bar, which is slidably mounted in the hollow stand 13, and is provided with holes 40 which may be moved into alignment withthe hole 41 in the bottom guide 42. Secured to the slide bar 39, as by rivets, is a bracket 43 which carries a collar 44 slidably mounted on a vertical guide bar 45. The lower end of this guide bar is carried by a bracket 46, and the upper end by a bracket 47 both of which are secured to and project from the rear part 15 of the stand. Preferably, the upper end of the guide bar 45 is secured to the bracket 47 by a pin 48.

49 is a compression spring, disposed around the guide bar 45 with its lower end .abutting against the bracket 46 and its upper end against the collar 44.

50 is a rack having teeth normally engaging the teeth of the pinion 21. The lower end of the rack is disposed between an extension of the bracket 43, and the slide bar 39, and is pivoted to them by 'a pin 51. 52 is a button or handle for the upper end of the rack. 53 is a pin, mounted in the upper end of the rack bar and normally held by a spring 54 in engagement with a hole in the slide bar 39 thereby retainingthe rack in engagement with the pinion. When this pin is retracted the rack may be disengaged from the pinion. Near the lower end of the rack, the teeth are cut away leaving a section 55 which iswithout teeth, which section comes opposite to the pinion 21, when the slide bar 39 and the rack 50 carried thereby have moved to the upper limit of their travel by the spring 49, so that when the rack is in such position the pinion 21 is free to rotate without obstruction or retardation of any kind.

56, is a pin slidably mounted in the front 'part 14 of the stand, which pin is normally forced inward by a spring 57 and which pin is provided with a button 58 by which it may be retracted.

In using the machine, the mold which is is to be used in the particular case is placed in the mold carrier 29, and the counter weight 24 is moved to the position where the arm is in balance. Thereafter the upper end of the rack may be released by retracting the pin 53, and moved to the right about its pivot pin 51 as shown in the drawings, by shifting the button 52 in that direction, and depressed, compressing the spring 49, and allowing the spring actuated pin 56 to engage the upper or lower hole 40 in the slide bar, depending on the amount of spring compression desired,

and lock the rack in such down position.

When this has been done and with the upper end of the rack still held to the right, whereby the teeth of the rack are held out of engagement with the pinion teeth, the throwing arm is brought to the horizontal position, shown in Fig. 1. The rack is then moved to the left into engagement with the pinion, and locked in such position by the spring actuated pin 53. The crucible is then filled in desired way with molten metal, and the button 58 pulled out to retract the pin 56 and release the slide bar 39. When this is done, the spring 49 which was compressed when the slide bar was forced down, throws this bar and the rack carried thereby upward at a rapid rate, spinning the pinion 21 and the throwing arm carried thereby, and throwing the molten metal outward into the mold. Then the rack reaches the upward limit of its movement, the teeth thereof pass out of engagement with the teeth of the pinion and leave the latter free to rotate without retardation of any kind, thus permitting rotation of the throwing arm to continue until .the metal in the mold has hardened.

Having described our invention, what we claim is:

1. In a .centrifugal casting machine, a throwing arm revolvable in a vertical plane, a pinion secured to and revolvable with said arm, a slid-e movable in a path tangential to said pinion, a rack having one end pivotally attached to said slide, said rack meshing with said pinion, and longitudinally movable with said slide to actuate said pinion, and being laterally shiftable to disengage it from said pinion to allow said throwing arm to be positioned, or said rack to be shifted.

2. In a centrifugal casting machine, a rotatable throwing arm, a mold carried thereby, and actuating means therefor, comprising a pinion and means securing said pinion to said arm, a slide longitudinally movable in a path tangential to said pinion, a rack pivotally attached at one end to said slide, a spring urging said rack laterally against said pinion, said rack having the teeth cut away adjacent said pivotal end, and being longitudinally slidable in mesh with said pinion, a spring urging said rack longitudinally, said rack being manually slidable to compress said spring and laterally shiftable to disengage said rack teeth. from and engage them with said pinion and a releasable stop engaging said rack-in shifted position.

3. In a centrifugal casting machine, a rotatable throwing arm, a mold carried thereby, and actuating means therefor, comprising a pinion, means securing said pinion to said arm, a slide longitudinally movable, a rack having one end pivotally attached to said slide, and having the teeth removed adjacent its pivoted end, and slidable in mesh with said pinion, a spring urging said rack longitudinally, said rack being manually slidable to compress said spring and lateral- 1y shiftable to disengage and re-engage. said rack and pinion, and a releasable stop engaging said slide after compressionof said spring.

4:. A casting apparatus comprising a stand, a shaft journalled therein, a throwing arm secured on said shaft outside said stand, a pinlon secured on sa1d shaft, a compresslon spring, a slide, a rack pivoted at one end I to said slide, a rack normally disengaged from said pinion, slidable longitudinally with said slide into engagement with said pinion and to compress said spring, and

means for releasably holding said slide in such position, said rack being laterally shiftable around said pivot to disengage said rack from said pinion.

5. In a centrifugal casting machine, including a throwing arm, and means for actuating same; a threaded and bored hub carried by said arm, said hub being longitu-- dinally slotted, a threaded sleeve on said hub, said sleeve having a slot complementary to said hub slot and an internal annular pinchamber, and a mold shell disposable within said hub, said shell having a projecting in insertable through said slots and co-opera 1e with said chamber to secure said sleeve in place. e I

6. Ina centrifugal casting machine, including a throwing arm, and means for actuating same; a threaded and bored hub car'- ried thereby, said hub being longitudinally slotted, a 'threaded'sleeve on said hub, and. a mold shell disposablewithinsaid hub, andsecured and clamped by said sleeve.

In testimony whereof we have hereunto set our names. v

CARL E. HUNTER. DE L. LUTZ. 

